Aft Hull Lines of Positioning Bow Type Self-propelled Cutter Suction Dredger(CSD) and their Hydrodynamic Performance

Objectives There is a large well in the stern to arrange cutter ladder for the positioning bow type Self-propellered CSD, which results in great difference on hydrodynamic performance from ordinary ships. By investigating hydrodynamic performance of two hulls with various stern shapes, namely twin deadwood and twin skeg, including calm water resistance behavior, stern wake field, wake fraction, and the nonuniform level of axial wake field, It provides scientific basic for rationally selecting and designing of stern lines for self-propelled CSD.Methods CFD(Computational Fluid Dynamics)method is applied to carry out simulation verification and validation of model resistance test. On this basis, hydrodynamic performance of the two hulls is compared and analyzed. Results At each of target speeds, the total resistance coefficient of twin skeg hull is lower than twin deadwood. At design speed, the total resistance coefficient of the former is 8.6% lower than the latter, while WOF(Wake Object Function) of the latter is judged to be better than the former by 11.0% from perspective of the nonuniform level of axial wake field.ConclusionsThe study results is of significant reference for lines design and optimization of similar hull type.